Building 4m wind turbines could power half the globe, say scientists

By JULIA HORTON
Published on 11/09/2012 01:19

WIND farms could produce enough power for half the world’s future energy needs with “negligible” harm to the environment, scientists believe.

Experts in America calculated that the amount of power which can be generated globally, using a 3D weather model to factor in the impact of turbines on the climate, such as their effect on surface temperatures and the natural circulation of air 
while they are in the process of producing power.

They found that the amount of electricity created increased in proportion to the number of turbines until a saturation point was reached, beyond which there were “too many turbines and not enough wind” and constructing more turbines would harm the environment without producing any more energy.

In theory they estimated this “saturation wind power potential” point could be more than 250 terawatts, far exceeding the world’s power needs.

In practice, they proposed a more cautious “fixed wind power potential”, representing the maximum power that can be extracted by a given number of turbines distributed over an increasingly large area.

Installing four million turbines globally could yield up to 7.5 TW per year with “negligible” impact on the climate, they found. That is still enough to meet over half the world’s power demand in 2030 which is estimated at about 11.5 TW of power every year.

Professor Cristina Archer, of Delawere University in Newark, said: “Everything comes at a price, but the price of wind power comes at a low cost in terms of climate impacts… wind power is very safe from the climate point of view.”

The study is published in Proceedings of the National Academy of Sciences.

The new research counters earlier research published last year by experts at the Max Planck Institute for Biogeochemistry in Germany who warned that wind energy could produce harmful effects similar in severity to doubling atmospheric carbon dioxide.

Prof Archer and her colleague, Prof Mark Jacobson, of Stanford University in California, conducted their own work in response, using a physical model to take real conditions into consideration – something they said the previous research lacked.

However Communities Against Turbines Scotland spokeswoman Linda Holt said: “Theoretically maybe they could produce all the world’s energy needs using wind power but this is just another theoretical model, it’s not based on empirical evidence.

“I don’t think it’s possible because they don’t factor in all the practicalities of connecting the wind to the grid.”

The Climate Change (Scotland) Act 2009 committed the Scottish Government to achieving a 42 per cent reduction in Scotland’s carbon emissions by 2020, rising to an 80 per cent reduction by 2050, compared to 1990 levels.